3 ms·
At work we've standardised on Baidu coordinates in China. Even though they're "encrypted", the encryption is locally smooth. Points may vary by 2km from their
by matthewrudy 11y ago
At work we've standardised on Baidu coordinates in China.
Even though they're "encrypted", the encryption is locally smooth.
Points may vary by 2km from their wgs84 equivalent, but taking two points 2km away, using the haversine formula will still yield a distance ~2km.
This means we can treat wgs84 and baidu-coordinates as equivalent, but not comparable, which makes a lot of things simpler.
Note: we don't do cross border orders, so we don't need to worry about cross border comparison.
Interestingly, Baidu uses it's own additional encryption on top of GCJ-02, so we are very much locked in
https://en.m.wikipedia.org/wiki/Baidu_Maps#Coordinate_system https://en.m.wikipedia.org/wiki/Baidu_Maps#Coordinate_system
- nightcracker 11y agoWhy do people call this encryption when in reality obfuscation is a much better word for it?
- easytiger 11y agohashing?
- masklinn 11y agoIt's not a hash since it's reversible.
- matthewrudy 11y agoI'm also wary of calling it encryption. But I don't think "obfuscation" or "hashing" are correct either. The intent is the same as encryption - to keep the real location a secret, available only to people with the key. It feels different because the encrypted value is basically an offset, and it's continuous, so it feels almost the same as the unencrypted form.